Sighting-in targets



Jam 21, 1964 I P. G. CURREN SIGHTING-IN TARGETS 2 Sheets-Sheet l FiledJan. 27, 1961 IN VEN TOR. Awu a cueesnl Jan. 21, 1964 P. G. CURREN 3,18,67

SIGHTING-IN TARGETS Filed Jan. 27, 1961 2 Sheets-Sheet 2 IN VEN TOR.P404 6'. CMQPEA/ ,arratn/Exs State Unite This invention relates broadlyto sighting-in weapons and is more particularly concerned with a targetfor the sighting-in of n'fles or the like on short target ranges for 11ran e firin 1i hun ting, aid particularly in large game hunting, therifle sights are often set for a range of 200 yards, or more. Theadjustment of the sights commonly referred to as sightiug-in for such arange is extremely important and must be accomplished with a high degreeof accuracy. Heretofore, to get this accuracy it has been nec essary touse a target range of the distance to which the rifle is to be sightedin. In many cases it is impossible to find a target range of sufficientlength so the sighting-in is done by approximation on shorter ranges,frequently 100 yard target ranges.

By one prior technique a standard target is placed at 100 yards. Therifle is aimed at the bulls-eye and fired. Preferably several rounds arefired to obtain a shot group. With this prior method the location of thegroup is visually observed. It, in the example distances cited, a groupappeared to be grouped about 3 inches above the center of the bulls-eyethe rifle has been considered sighted in. This method is quiteinaccurate and subject to many errors.

This invention overcomes these and other limitations of the prior art ofsighting-in.

This invention utilizes what is known as trajectory height which can beaccurately determined in conjunction with a target having an aimingbulls-eye spaced a predetermined and preselected distance below thescoring bulls-eye on a conventional target. Trajectory height, as usedherein, means the height of the parabolic path of travel of a roundabove the line of sight at a given point. Broadly speaking, according tothis invention a sighting bulls-eye is placed on the line of sight and ascoring bullseye on the determined parabolic path of travel.

A principal object of this invention is to providea target usable on ashort target range to sight-m a rifle or the like for long range firing.

A more particular object of this invention is to prov de a targetaccording to the above object having a sighting bulls-eye and a scoringbulls-eye in a predetermined vertical spaced relationship.

A more specialized object of this invention is to provide a target forsighting-in rifle having a contrasted sighting bulls-eye verticallyspaced from the scoring bulls-eye a predetermined distance.

Other objects and fuller understanding of the invention may be had byreferring to the following description and claims taken in conjunctionwith the accompanying drawings in which:

, FIG. 1 is a diagrammatic representation of a rifle being sighted on ashort target range for long range sightingin showing the line of sightand the parabolic trajectory path of a round fired for a given longrange distance with a target interposed at the shorter range, with thetarget being shown rotated 90, and with both the rifle and the target ona greatly enlarged scale with respect to the range distance.

FIG. 2 shows a target having a scoring bulls-eye and concentric scoringrings and a sighting bulls-eye spaced below the scoring bulls-eye incontrast with its background.

FIG. 2a is an adhesive-backed sighting bulls-eye to be placed on anyexisting target, selectively securable to any desired trajectory height;

FIG. 3 is an alternate embodiment of FIG. 2;

FIG. 3a is an adhesive-backed sighting bulls-eye to be placed on anyexisting target, selectively securable to any desired trajectory height;

FIG. 4 is another alternate embodiment of FIG. 2; and

FIG. 4a is an adhesive-backed sighting bulls-eye to be placed on anyexisting target, selectively securable to any desired trajectory height.

Referring now to the drawings and particularly FIG. 1, the target andmethod of sighting-in are shown.

The rifle to be sighted in its designated by the reference character 10.The rifle 10 includes a muzzle 11 and a sighting device 12. The angularrelationship between the sighting device 12 and the muzzle 11 can bechanged. The line of sight of the sighting device is shown by a brokenstraight line 13. The path of a fired round is designated by the brokenline 14. Due to the force of gravity, a round fired from the rifle 10will not follow a straight line when it leaves the muzzle 11, but willfollow the curved path 14 which is substantially parabolic.

This parabolic trajectory path intersects the line of sight at a downrange point 15. It will be noted that the lines 13, 14, also intersectnear the rifle 10. Because of the distance involved this crossing can betreated as if it occurs at the end of the muzzle 11. The said roundtravels along the path 14 to a high point 16 which is located about onehalf the distance from the end of the muzzle 11 to the down range point15. The height of this path 14- above the line of sight 13 at any pointis known as the trajectory height. The trajectory height of the point 16is known as the mid-range trajectory.

The principle involved in sighting-in a rifle is to set the line ofsight 13, and the trajectory path 14 such that the down range point ofintersection 15 is at a known distance from the rifle 19. Three factorsinfluence the location of this point 15:

(l) Muzzle velocity of the round;

(2) Weight of the projectile; and

(3) The angle of inclination of the muzzle, with the line of sight.

With any given rifle and type of cartridge the first two of these areconstant and known or determinable. Hence, if the angle of inclinationis set at a predetermined value the trajectory path 14 and the point 15are located for all of a given type of cartridge fired from a givenrifle. If a target is placed a distance from the rifle equal to thedistance of the point 15 from the rifle and the line of sight ispositioned to intersect the bulls-eye of the target, a round fired ofthe given type of cartridge will follow the path or" travel 14 andstrike the bulls-eye. If,

- however, the target is placed closer to the rifle than the distanceequal to the distance of the point 15 from the rifle, the projectilefollowing the trajectory path will strike the target at a point abovethe line of sight 13.

-In order to sight in a rifle for a given distance, one

I method is to place a target at the distance to which the rifle is tobe sighted in, aim the rifle so that the line of sight passes throughthe bulls-eye and fire one or more rounds. The target is then examinedto see the position of the shots and if such position is not correct theangle between the line of sight and the trajectory path is adjusted andthe firing done again until the shots are properly placed.

This method of sighting in requires a target range having a distanceequal to the range to be sighted in. Finding a suitable range longenough is often impossible, especially for sighting in for a range morethan yards.

The present invention makes use of the fact that the trajectory path 14can be determined and its height above the line of sight 13 can thus beascertained. According to the present invention a target 20 is placed agiven distance from the rifle, but at a range shorter than thesighting-in range. The target will include a conventional scoringbulls-eye 21 and scoring rings 22 and additionally will include asighting bulls-eye 26. The sighting bullseye 26 is so placed in relationto the scoring bulls-eye that when the line of sight 13 passes throughthe center of the sighting bulls-eye 26 the determined trajectory heightat the target range will be located at the center of the scoringbulls-eye 21. Thus, to sight in a rifle for 200 yards a target may beplaced at 100 yards. The trajectory height of a given type of ammunitionis then determined at 100 yards for a 200 yard sight setting and thecenter of the sighting bulls-eye 26 is placed exactly that distancebelow the center of the scoring bulls-eye 21. When'the line of sight ofthe trifle is adjusted so that it passes through the center of thesighting bulls-eye 26 and the angle of the rifle muzzle with the line ofsight is correct for 200 yards, the trajectory height of the projectileat 100 yards will pass through the center of the scoring bulls-eye. Thusa round fired from the rifle will pass through the center of the scoringbulls-eye 21.

To sight-in a rifle the selected sighting-in range is determined and thetarget range is selected. The trajectory height at the target range isthen ascertained. The target 20 is placed at the target range distancefrom the rifle and the center of the sighting bulls-eye 26 is placed adistance below the center of scoring bulls-eye 21 which is equal to theascertained trajectory height. A rifle is then aimed at the sightingbulls-eye 26 so that the line of sight passes through the sightingbulls-eye 26 and at least one and preferably a group of rounds arefired. The target is then examined to determine the position of theshots with respect to the scoring bulls-eye. If they are not properlyplaced therein the angle of the muzzle with respect to the line of sightis changed and another group of rounds is fired and the target againexamined. The firing, examining of the target, and correcting of thesights is repeated until the shots are properly placed in the scoringbulls-eye 21.

The trajectory heights of various types of ammunition can be obtained,and the following table gives representative mid-point trajectories forvarious types of commonly used big game ammunition.

Midrange Trajectory in Inches Cartridge 100 Yards 200 Yards Yards .270Winchester .270 Winchester .300 Weatherly Magnum.

Example I Assume that the cartridge to be used is a .270 Winchester witha 150 grain bullet, and the rifle is to be sighted in for 200 yardszero, and the available target range is 100 yards. The target is placedat the 100 yard range. Reference to the table above indicates that themid-point trajectory for this round is 3.0 inches. A target is selectedor prepared that has the center of the sighting bulls eye 26, 3.0 inchesbelow the center of the scoring bulls-eye 21. The rifle is sighted atthe sighting bulls-eye 26 and several rounds of the selected cartridgeare fired. The position of the shot group is observed and necessarysight adjustments made. A rifle so sighted in would deliver a hit in thekilling zone of an animal as small as a Pronghorn antelope at anydistance from 4 the gun muzzle up to 400 yards even if the range ismisjudged.

If the exact trajectory height is not readily available for the desiredsighting-in range and the target range combination it can be veryclosely approximated in most cases by interpolation and exterpolation.

Example 11 3.0-HA (7.83.0)=3.0+% (4.8)=3.0+3.6:6.6 inches This equalsthe trajectory height at the mid-point of 275 yards, i.e. 137.5 yards.Therefore, the trajectory height at 160 yards would be approximatelyequal to:

IHChGS Thus, for sighting in of the rifle for 275 yards with the targetat a range of 100 yards the center of the sighting bulls-eye 26 shouldbe placed 4.8 inches, below the center of the scoring bulls-eye 21. Thisis diagrammatically represented in FIGURE 1. Other combinations arereadily apparent.

Another advantage, not so readily apparent, is the usefulness of thistarget placement and sighting in, in correcting canting tendencies onthe part of the rifieman. Canting is the twisting of the weaponrotatably on the axis of the barrel so that the sights are not on avertical plane passing through the barrel of the rifle. A 5 cant willshow up in this shot grouping as about a 2-inch lateral displacement at100 yards, and an 8 to 10 inch lateral displacement at 200 yards.

FIGURES 2 through 4a show several embodiments of targets for sighting inrifles according to this invention. The target 20 has a scoringbulls-eye 21 and a plurality of scoring rings 22. The bulls-eye iswhite, and the two innermost scoring rings 22 are black. The remainingscoring rings are colored white. A sighting disc 25 is provided having asighting bulls-eye 26 thereon. Preferably the disc is sized to the sizeof the scoring bullseye. This sighting bulls-eye 26 may be printed orformed integral with the remainder of the target, or it may be printedon a separate material with adhesive backing suitable to afiix thebulls-eye on the target at a selected position to correspond with thedetermined trajectory height.

In FIGURES 2 and 2a, the sighting bulls-eye 26 has its upper portioncolored white and its lower portion colored black. This is to affordcontrast with the scoring rings upon which it is normally superimposed.

FIGURES 3 and 3a show another arrangement of contrasting appearances asdo FIGURES 4 and 4a. In FIGURE 4, the appearance of the sightingbulls-eye of the sighting disc 25 contrasts with the appearance of thesighting ring around the sighting bulls-eye, and the appearance of thesighting ring contrasts 'with the appearance of the adjacent portions ofthe scoring rings on the scoring target. The contrasting appearances ofthe sighting disc 25 are contoured to complete the contour of theadjacent scoring rings on the scoring target.

Although the invention has been described in detail, it is believed tocomprise essentially a target for sighting in a rifle or the like for along range using a short range, tha target having a scoring bulls-eyeand contrasting scoring rings around the scoring bulls-eye, a sightingbullseye of substantially the size of the scoring bulls-eye positionedamong the scoring portions and having its center located a predeterminedmid-range trajectory height from the center of the scoring bulls-eye,and the sighting bulls-eye having its surface appearances in contrastingrelation to the adjacent scoring portions of the target for thatpredetermined mid-range trajectory height.

What is claimed is:

1. The combination for sighting-in a rifle or other arms for accuratefiring of a missile from full-size ammunition over a distance greaterthan the available range between the rifle and a target sheet, saidcombination comprising:

(a) the target sheet having:

(i) a circular bulls-eye scoring portion;

(ii) a plurality of ring scoring portions concentrically arranged withrespect to one another and with respect to said bulls-eye scoringportion;

(iii) said bullseye scoring portion and at least one of said ringscoring portions having contrasting colors;

(b) a sighting disc being removably secured to the target sheet so as tobe superimposed over the scoring portions with the center of saidsighting disc spaced from the center of said bulls-eye scoring portion apredetermined distance equal to the trajectory height of the missilefired when the missile is at the available range distance of the totaldistance for which the rifle is being sighted-in;

(c) said sighting disc having a central bulls-eye sighting portion; and,

(d) said bulls-eye sighting portion being colored to contrast with theadjacent scoring portions when the center of said sighting disc isspaced said predetermined distance from the center of said bulls-eyescoring portion.

2. The combination of claim 1, including, in combination:

(e) said sighting disc further having a circle sighting portionsurrounding said bulls-eye sighting portion, and said circle sightingportion being colored to contrast with the coloring of said bulls-eyesighting portion.

3. The combination for sighting-in a rifle or other arms for accuratefiring of a missile from full-size ammunition over a distance greaterthan the available range between the rifle and a target sheet, saidcombination comprising:

(a) the target sheet having:

(i) a circular bulls-eye scoring portion;

(ii) a plurality of ring scoring portions concentrically arranged withrespect to one another and with respect to said bulls-eye scoringportion;

(iii) said bulls-eye scoring portion and at least one of said ringscoring portions having contrasting colors;

(b) a sighting disc being removably secured to the target sheet so as tobe superimposed over the scoring portions with the center of saidsighting disc spaced from the center of said bulls-eye scoring portion apredetermined distance equal to the trajectory height of the missilefired when the missile is at the available range distance of the totaldistance for which the rifle is being sighted-in;

(c) said sighting disc having:

(i) a central bullseye sighting portion; and,

(ii) a ring sighting portion surrounding said bullseye sighting portion;

(d) the coloring of the sighting portions contrasting with the coloringof the scoring portions; and,

(e) the coloring of said sighting portions being contoured to completethe circular contour of the adjacen-t scoring ring portions in thecontrasting colored relation when the center of the scoring disc isspaced said predetermined distance from the center of said bulls-eyescoring portion.

4. The combination of claim 3 including, in combination:

(1) the coloring of said ring sighting portion contrasting with thecoloring of the adjacent ring scoring portions and the coloring of saidbulle-eye sighting portion contrasting with the coloring of the ringsighting portion.

5. The combination of claim 3 wherein said contrasting colors are thecolors black and white.

6. The combination for sighting-in a rifle or other arms for accuratefiring of a missile from full-size ammunition over a distance greaterthan the available range between the rifle and a tanget sheet, saidcombination comprising:

(a) the target sheet having:

(i) a circular bull -eye scoring portion;

(ii) a plurality of ring scoring portions concentrically arranged withrespect to one another and with respect to said bul-ls-eye scoringportion;

(iii) said bulls-eye scoring portion and at least one of said ringscoring portions having contrasting colors;

(b) a sighting disc being removably secured to the target sheet so as tobe superimposed over the scoring portions with the center of saidsighting disc spaced n'rom the center of said bulls-eye scoring portiona predetermined distance equal to the trajectory height of the missilefired when the missile is at the available range distance of the totaldistance for which the rifle is being sighted-in;

(c) said sighting disc having a central bulls-eye sighting portion;

(d) said bulls-eye sighting portion being colored to contrast with theadjacent scoring portions when the center of said sighting disc isspaced said predetermined distance from the center of said bulls-eyescoring portion; and

(e) the coloring of said bulls-eye sighting portion being contoured tocomplete the contour ofadjacent scoring portions in the contrastingcolor relation.

7. A tanget for sighting-in a rifle or like arms for the accurate firingof a missile from full-sized ammunition over a distance greater than theavailable range between the rifle and the target, said targetcomprising:

(a) a circular bulls-eye scoring portion;

(b) a plurality of ring scoring pontions concentrically arranged 'Withrespect to one another and with respect to said bullseye scoringportions;

(c) the surface of said bulls-eye scoring portion and the surface of atleast one of said ring scoring portions having contrasting appearances;

(d) a circular bulls-eye sighting portion of at least nearly the size ofsaid bulls-eye scoring portion being positioned among said scoringportions and having its center located a predetermined distance from.the center of said bulls-eye scoring portion, said predetermineddistance being equal to the trajectory height of the missile when it isat the available range distance of the total range for which the rifleis being sighted-in; and,

(e) the surface of said bulls-eye sighting portion having an appearancecontrasting with adjacent scoring portions when its center is locatedsaid predetermined distance from the center of said bulls-eye scoringportion.

8. The combination of claim 7 including, in combination:

(f) the contrasting surface appearance of said bullseye sighting portionbeing contoured to complete the circular contour of said ring scoringportions in the contrasting surface appearance relation.

9. The combination of claim 8 including, in combination:

(g) a ring sighting portion surrounding said bulls-eye sighting portionand the surface of said ring sighting portion having an appearancecontrasting with 7 the surface appearance of said bullseye sightingportion.

10. A target for sightingin a rifle or like arms for the accurate firingof 'a missile from full-sized ammunition over a distance greater thanthe available range between the rifle and the target, said targetcomprising:

(a) a circular bulls-eye scoring portion;

(11) a plurality of ring scoring portions concentrically arranged withrespect to one another and with respect to said bulls-eye scoringportion;

(c) the surface of saidbulls-eye scoring portion and the surface of atleast one of said ring scoring por tions having contrasting appearances;

(d) a circular bulls-eye sighting portion of at least nearly the size ofsaid bulls-eye scoring portion being positioned among said scoringportions and having its center located a predetermined distance from thecenter of said bulls-eye scoring portion, said predetermined distancebeing equal to the trajectory height of the missile when it is at theavailable ra-nge distance of the total range for which the rifle isbeing sighted-in;

(e) a ring sighting portion surrounding said bulls-eye sighting portion;

(f) the surface appearance of said ring sighting portion contrastingwith the surface appearance of the adjacent ring scoring portions, andthe surface appearance of said bulls-eye sighting portion contrastingwith the surface appearance of said ring sighting portion; and,

(g) the surface appearance ofsaid ring sighting portion andsaidbulls-eye sighting portion being contoured to complete the circularcontour of the ring :scoring portions in the contrasting surfaceappearance relation.

11. The combination of claim 7 wherein said bulls-eye sighting portionis adjacent at least two scoring portions of contrasting surfaceappearance and is provided with said contrasting surface appearances,and the contrasting surface appearances being contoured to complete thecircular contour of the adjacent scoring portions in the contrastingsurface appearance relation.

12. The combination of claim 10 wherein said sighting portions areadjacent at least two scoring portions of contrasting surfaceappearances, both said ring and bullseye sighting portions beingprovided with the contrastirn surface appearances of the adjacentscoring portions, the surface appearance of the ring sighting portionbeing contoured to at least partially complete the circular contour ofthe adjacent scoring ring portions in the contrasting surface appearancerelation, and the surface appearance of said bulls-eye sighting portioncontrasting References Cited in the file of this patent UNITED STATESPATENTS Gandet Sept. 15, 1903 Murphy Nov. 28, 1939

1. THE COMBINATION FOR SIGHTING-IN A RIFLE OR OTHER ARMS FOR ACCURATEFIRING OF A MISSILE FROM FULL-SIZE AMMUNITION OVER A DISTANCE GREATERTHAN THE AVAILABLE RANGE BETWEEN THE RIFLE AND A TARGET SHEET, SAIDCOMBINATION COMPRISING: (A) THE TARGET SHEET HAVING: (I) A CIRCULARBULL''S-EYE SCORING PORTION; (II) A PLURALITY OF RING SCORING PORTIONSCONCENTRICALLY ARRANGED WITH RESPECT TO ONE ANOTHER AND WITH RESPECT TOSAID BULL''S-EYE SCORING PORTION; (III) SAID BULL''S-EYE SCORING PORTIONAND AT LEAST ONE OF SAID RING SCORING PORTIONS HAVING CONTRASTINGCOLORS;